Frequently the driving wheels of a motor vehicle become stuck in mud, sand or snow in the operation of the vehicle; so that the necessary traction for moving the vehicle either forward or backward cannot be developed by the stuck driving wheel. This is true of four-wheel drive vehicles and vehicles with positive traction differentials as well as conventional motor vehicles. Such situations frequently arise in areas having heavy snow or with four-wheel drive vehicles which are driven into remote areas where they frequently encounter deep mud or sand. Usually when a motor vehicle becomes stuck, it must be dug out of the snow, mud or sand which is a long and arduous task. Frequently, the vehicle cannot be dug out, and it is necessary to tow the vehicle with a tow truck or other vehicle until it is moved to a place where proper traction can be obtained for the driving wheels.
Separate, electric-powered winches are available for motor vehicles and these are frequently employed in off-road or four-wheel drive vehicles. Such separate winches, however, are cumbersome and unsightly in appearance. In addition, they are expensive and require special installation on the vehicle.
Other attempts have been made in the past of utilizing permanently attached winch drums attached to the driving wheels of the vehicle. These interfere with the operation of the vehicle in rocky or rugged terrain or even in parking the vehicle adjacent the curbs commonly employed along the edges of streets. When such fixed winch drums strike a rock or a curb they are easily damaged and impart unnatural stresses to the driving wheel components to which they are attached.
Other attempts in the past have been made to employ removable wheel winch drums. Some of these utilize a permanently attached adapter which is held in place by the wheel lug bolts used to attach the vehicle wheel to the axle. A second part then is employed to complete the drum when it is desired to use it; but these multipart assemblies are relatively expensive, and the permanent attachment of a portion of the assembly to the vehicle wheel is not particularly desirable since it unnecessarily complicates the changing and rotation of tires on the vehicle. Other prior art one-piece winch drums are difficult to attach and remove because of interference of the outer flange with the use of a lug wrench.
It is desirable therefore to provide a simple winch drum construction for removable attachment to the wheel of the vehicle when the vehicle is stuck and it is necessary to use the winch to assist in removal of the vehicle to a place of positive traction. It is further desirable to construct a removable wheel winch in a manner which facilitates its easy attachment and removal from the vehicle wheel.